lzdip.exe doesn't work under 64bit operating system (Vista or 7). It needs modern alternative.
Unfortunately I don't have a 64bit OS. So I can't test. The ldzip.exe is included with mrunos backup module. I could probably do some edits on it to make it work better with a different console/command-line compression program that is compatible with 64bit Windows. Do you know if PKZIPc works? (console version of pkzip)
ldzip.exe doesn't work because it's 16bit program, and those are not supported on 64bit anymore.
Just tested pkzipc 4.0 and the newest from their website (12.4?) their both work. I would gladly help to test any changes in backup module.